The present invention relates to a method and system for controlling the active power output of a wind farm, comprising a plurality of wind turbines.
With increasing use of wind turbines, whether on land or at sea, the importance thereof to the electrical power grid is increasing. Consequently with regard to infeeding active power, given setpoints for the active power fed into the grid connection point must be precisely maintained. This relates to both the stationary state in which—provided there is enough wind—a constant amount of active power is fed in, and the dynamic behavior in which a setpoint setting is varied over time and/or changeable wind conditions exist.
A wind farm control with an improved setpoint behavior has been disclosed in DE 10 2014 000 790 A1. The wind farm has a farm master with a power controller for controlling the wind turbines contained in the wind farm. A setpoint for the power output of the wind farm is applied to the farm master and is output for the wind turbines as setpoint signals for the power output. The setpoints for the wind turbines are corrected if there is a change in the setpoint signal for the wind farm, wherein the corrected setpoint is injected into the power controller. The setpoint for the wind turbine is calculated using a predictor, wherein in so doing, different operating states of the wind turbines and different power values are taken into consideration.
A wind farm with a feed-forward control in the power controller has been disclosed in DE 10 2014 000 784 A1. The wind farm has a farm master designed to manage the wind turbines, wherein the farm master comprises a power controller. The power controller has a feed-forward control module that injects a level for the target power via a multiplication element into the output of the power controller. This is to achieve accelerated response behavior of the feed-forward control when there is a setpoint reduction and create robust response behavior of the wind farm.